3-Hexanone (CAS 589-38-8): Global Supply & Tech Guide
Introduction:As a specific C6 ketone isomer, 3-hexanone (Ethyl Propyl Ketone) offers unique volatility and solubility profiles compared to MEK or MIBK. For formulators and procurement managers, choosing 3-hexanone isn’t just about sourcing a solvent; it’s about optimizing coating leveling and controlling reaction selectivity. This guide covers everything from detailed physicochemical properties to global DG logistics compliance for Shandong Look Chemical’s 3-hexanone.
Table of Contents
- Product Identification and In-Depth Analysis of Molecular Structure
- Technical Interpretation of Physicochemical Properties
- Industrial Production Process and Impurity Control Strategy
- Deep Application: From Formulation to Synthesis
- Global Logistics, Packaging and Warehousing Specifications
- Health, Safety and Environment (HSE) in Depth Guide
- Procurement Proposal
- Extended Version FAQ
- Our Laboratory and References
Product Identification and In-Depth Analysis of Molecular Structure
Accurate chemical labeling is the cornerstone of international trade compliance. When dealing with import and export customs declaration, REACH registration and inventory management, the accuracy and consistency of the following identifiers are critical:
| Identifier Type | Value |
|---|---|
| IUPAC Name | Hexan-3-one |
| Common Name | Ethyl Propyl Ketone |
| CAS Number | 589-38-8 |
| EC Number | 209-645-4 |
| Molecular Formula | C₆H₁₂O |
| Molecular Weight | 100.16 g/mol |
Structural Isomers and Regioselectivity:
In the C6 ketone family, 3-hexanone is often confused with 2-hexanone (methyl butyl ketone, MBK, CAS 591-78-6). Although the molecular weights of the two are the same, the different carbonyl positions lead to huge differences in properties, which is what researchers must be alert to:
Differences in symmetry and polarity
Toxicological and metabolic mechanism
Synthetic reaction activity
Differences in symmetry and polarity
2-hexanone is a methyl ketone with slightly higher polarity; while 3-hexanone is ethyl propyl ketone, the carbonyl group is located closer to the center of the molecular chain compared to 2-hexanone, offering a more balanced steric structure. This small geometric difference will affect its dipole moment, and then change its solubility to specific resins as a solvent.
Toxicological and metabolic mechanism
2-hexanone can be metabolized in vivo to produce 2,5-hexanedione, which is a known neurotoxin that can cause peripheral neuropathy. In contrast, 3-hexanone has different metabolic pathways and usually does not produce such highly toxic metabolites. This makes 3-hexanone a safer alternative to 2-hexanone in some formulations with strict toxicological requirements.
Synthetic reaction activity
In the reactions involving α – hydrogen (such as aldol condensation and alkylation), the carbonyl group of 3-hexanone is flanked by ethyl and propyl groups respectively, and its steric hindrance effect is significantly greater than that of the methyl side of 2-hexanone. This means that 3-hexanone can provide different product distributions when controlling the regioselectivity of the reaction.
Technical Interpretation of Physicochemical Properties
This chapter will further explore the guiding significance of the physical parameters in practical industrial applications.
1.volatilization characteristics and drying kinetics:
| Property | Value/Range | Method / Condition |
|---|---|---|
| Boiling Point | 123 °C | 101.3 kPa |
| Vapor Pressure | 12 – 15 mmHg | 25 °C |
| Flash Point | 26 °C - 30 °C | Closed Cup |
| Density | 0.82 g/cm³ | 20 °C |
| Evaporation Rate | 0.4 – 0.5 | vs. Butyl Acetate = 1 |
In the paint industry, the evaporation rate of solvent determines the quality of paint film. 3-hexanone is considered a “medium-to-slow evaporating solvent“.
In a humid climate, rapidly volatile solvents (such as acetone) will take away a large amount of latent heat of evaporation, causing the surface temperature of the paint film to drop below the dew point, condensing water vapor and turning white. The moderate volatility of 3-hexanone can maintain the surface temperature and effectively prevent this defect.
In large-scale industrial spraying, it is necessary to maintain a wet edge for subsequent spraying and lapping. 3-hexanone can significantly prolong the wet edge time and reduce lap marks.
2. solubility parameters
In order to scientifically predict the solubility in 3-hexanone to different resins, we introduced Hansen solubility parameter (HSP). Although the specific values fluctuate slightly with the test method, the typical range is as follows:
| Component | Symbol | Value (MPa^0.5) |
|---|---|---|
| Dispersion Force | δD | 15.8 |
| Polarity | δP | 6.0 |
| Hydrogen Bonding | δH | 5.0 |
This set of parameters shows that 3-hexanone has excellent affinity for resin systems with medium polarity.
Nitrocellulose (NC): an excellent true solvent, the generated solution has low viscosity, allowing the increase of solid content.
Polyurethane (PU): as an auxiliary solvent, it is used in combination with ester solvents to adjust the viscosity of the system.
Acrylic resin: it has strong solubility in thermoplastic acrylic resin and is commonly used in automotive refinish coatings.
3. water organic phase partitioning behavior
Application interpretation: unlike acetone or tetrahydrofuran, which are completely water-soluble, 3-hexanone is only partially miscible with water. This feature is invaluable in the extraction process.
Phase separation: in the post-treatment of organic synthesis, when water is added for washing, 3-hexanone can rapidly separate from the aqueous layer, and the emulsification tendency in the aqueous phase is low, the interface is clear, and the static stratification time is greatly shortened.
Industrial Production Process and Impurity Control Strategy
1. main synthetic route
2. Impurity Profile
3. QC Methodology
1. main synthetic route
Shandong Look Chemical Co., Ltd. adopts the currently mainstream 3-hexanol catalytic dehydrogenation process in industrial production.
Reaction principle: take 3-hexanol as raw material, remove a molecule of hydrogen under high temperature (250-350 ° C) gas phase conditions under the action of copper or zinc catalyst.
Process advantages: high conversion rate and few side reactions. Compared with carboxylic acid decarboxylation method or oxidation method, this route does not introduce heavy metal oxidants and is more environmentally friendly.
2. Impurity Profile
Although our factory purity is set at ≥ 99.0%, for precision applications, it is important to understand what the remaining <1.0% is.
3-hexanol (raw material residue): usually controlled at <0.3%. The presence of alcohol will introduce active hydrogen. If customers use it in isocyanate curing system (PU coating), alcohol will consume curing agent (NCO group), resulting in the decrease of cross-linking density of paint film.
3-hexene (dehydration by-product): trace presence. Alkenes are usually unstable and prone to oxidative discoloration. We reduce it to ppm level by precision distillation.
2-hexanone (isomerization by-product): a very small amount of isomerization may occur during the catalytic process. We focus on monitoring this item in QC to control the isomeric impurity (2-hexanone).
Moisture: through molecular sieve dehydration tower, we control the moisture at a very low level to prevent quenching of the customer’s Grignard reagents or organolithium reagents.
3. QC Methodology
The Central Laboratory of Shandong Look Chemical Co., Ltd. follows ASTM and ISO standard methods:
Main content: use a gas chromatograph (GC-FID) equipped with a capillary column (such as HP-5 or DB-WAX). The area normalization method can be used for routine release (applicable to scenarios where the response of known impurities is close), such as for high-precision quantification. It is recommended to adopt the external standard / internal standard method and establish the impurity response factor.
Moisture: Karl Fischer coulometric titration. Compared with volumetric method, coulometric method has higher detection accuracy and better repeatability for trace moisture (<0.1%).
Acidity: automatic potentiometric titration. Titration with sodium hydroxide standard solution, the detection endpoint is sensitive, and the error of artificial observation of indicator discoloration is eliminated.
Deep Application: From Formulation to Synthesis
1. electronic chemical cleaning agent
2. pharmaceutical intermediates
3. flavor and fragrance industry
1. electronic chemical cleaning agent
With the development of electronic components to miniaturization, the requirements for cleaning solvents are increasingly stringent.
Removal of flux: 3-hexanone has excellent solubility for rosin based flux.
Low surface tension: its low surface tension enables it to penetrate into tight gaps (such as the bottom of BGA package) for cleaning.
Halogen free: This product contains no halogenated solvents. Compliance with RoHS/REACH shall be assessed at the finished product/formulation and supply-chain declaration level.
2. pharmaceutical intermediates
In chiral drug synthesis or complex molecular construction, solvent is not only a medium, but also a participant.
Reaction temperature control: the boiling point of 3-hexanone at 123 ° C provides an ideal “medium temperature” reaction window. Compared with toluene (110 ° C), it allows a slightly higher reaction temperature to increase the rate; Compared with xylene (140 ° C), it is easier to remove by vacuum distillation after the end of the reaction.
Aprotic polar environment: as an aprotic polar solvent, it can promote the nucleophilic substitution reaction of SN2, while avoiding the side reactions of solvent decomposition that may be brought by protic solvents (such as alcohols).
3. flavor and fragrance industry
In fragrance formulations for household and personal care products, 3-hexanone not only provides its own “fruity, ethereal” top note, but also acts as a fixative because of its moderate volatility, helping the more volatile ester flavor to remain longer.
Global Logistics, Packaging and Warehousing Specifications
In order to ensure that the products will not be polluted during the months of shipping, we have strict requirements for packaging materials.
170kg tight head steel drums
Material: cold rolled steel plate.
Internal coating: considering that ketone solvents have certain permeability and swelling, we usually recommend using clean unlined steel drum, or using epoxy phenolic internal coating that has been tested for ketone resistance. Ordinary PVF coatings may be dissolved by ketones, resulting in product contamination.
Sealing: standard 2-inch and 3/4-inch Tri-Sure® bungs are used, with cap-seals and solvent resistant gasket (such as EPDM or PTFE gasket). Note: Compatibility of FKM/Viton depends on the specific grade and should be confirmed by permeation/swelling tests; some ketone services may cause swelling.
ISO TANK
Cleaning standard: before each loading, the “cleaning certificate” of the third-party cleaning station must be issued to ensure that there is no residue of the above category of goods in the tank, no odor, and it has been dried.
Inert gas protection: it is recommended to flush high-purity nitrogen (nitrogen blanket) after loading to replace the air on the tank top. This can not only prevent oxidation discoloration, but also reduce ignition and explosion hazards in the vapor space during transportation.
For post-purchase storage, we recommend that customers follow the following specifications:
First in first out (FIFO): strictly implement the principle of first in first out to avoid slight increase in acidity due to long-term inventory.
Grounding protection: Like many organic solvents, 3-hexanone can accumulate static charge during flow. All flanges, valves and pump bodies in the storage tank farm must be jumper connected and grounded. The feed pipe should extend to the bottom of the tank (submerged feed) to avoid electrostatic accumulation due to splashing.
Breather valve: the storage tank shall be equipped with a breather valve with flame arrester, and a dryer (silica gel or molecular sieve) shall be installed on the breather pipeline to prevent moisture in the air from being inhaled and causing the product moisture to exceed the standard.
| Regulatory Parameter | Description / Value |
|---|---|
| UN Number | 1224 |
| Proper Shipping Name (PSN) | KETONES, LIQUID, N.O.S. (Hexan-3-one) *Note: Technical name (Hexan-3-one) is mandatory |
| IMO Class | 3 (Flammable Liquid) |
| Packing Group | III (Low Danger) |
| EMS Guidelines | F-E (Fire), S-D (Spillage) |
Health, Safety and Environment (HSE) in Depth Guide
Acute toxicity:
LD50 oral (rat) ≈ 2738 mg/kg; LD50 percutaneous (rabbit) ≈ 2583 mg/kg
Irritant: irritating to eyes and respiratory mucosa. Inhalation of high vapor concentrations may cause dizziness and anesthesia (central nervous system depression).
Carcinogenicity / mutagenicity: the existing public data and SDS of some suppliers do not suggest that they have clear evidence of carcinogenicity; Genotoxicity / mutagenicity conclusions shall be subject to specific research and regulatory database entries.
Not all gloves are protective against ketone solvents. This is the most common mistake in field operation.
Recommended gloves:
Butyl rubber: the protective effect is the best, and the breakthrough time is >480 minutes.(Actual performance depends on glove thickness and EN 374 / ASTM F739 permeation data.)
EVOH (ethylene vinyl alcohol copolymer): composite membrane gloves with excellent effect.
Do not use:
Natural latex (latex): it will penetrate and swell in a few minutes.
Nitrile rubber: disposable thin nitrile gloves are generally only suitable for short-time splash protection against a variety of organic solvents, and the manufacturer’s penetration test data shall prevail.
Evacuation and warning: evacuate nonessential personnel immediately and set a warning line around the leakage area.
Cut off the fire source: turn off all power supplies and engines in the area, and prohibit the use of non explosion-proof communication tools.
Containment: use explosion-proof pump or spark free tool to transfer a large amount of leakage liquid. Use sand to build a dike to prevent it from flowing into the sewer.
Adsorption: use vermiculite, perlite or special oil absorbent pads to adsorb a small amount of residue. Do not use sawdust (flammable).
Post treatment: put the saturated waste into a sealed metal container and send it to a qualified hazardous waste treatment company for incineration.
Procurement Proposal
1. in order to reduce repeated communication and ensure that the supply plan of Shandong Look Chemical Co., Ltd. accurately matches your needs, it is recommended to provide:
Destination country and port / Airport (involving dangerous goods booking and document template)
Use (solvent / synthesis / cleaning / other)
Annual consumption or single purchase volume (determine the packaging and logistics plan)
Preferences for key indicators (purity, moisture, acidity, whether typical chromatography is required)
Whether samples need to be transported by air (different requirements for dangerous goods express)
2. suggestions on arrival acceptance
Check the package integrity and label information (CAS, batch number, net weight, dangerous goods identification);
Check that the COA is consistent with the actual batch number;
Sample to confirm the appearance (clear and free of visible impurities);
Retest of key indicators (usually GC purity and moisture);
After warehousing, it shall be managed according to the flammable liquid, and the first in first out (FIFO) and unsealing management records shall be established.
Extended Version FAQ
This section summarizes the high-frequency and deep-seated problems we have encountered in technical exchanges with multinational pharmaceutical companies, coating giants and distributors in the past five years.
A: 3-hexanone is chemically stable. If stored in sealed, nitrogen filled and light protected original packaging, its physical and chemical properties will hardly change within 2 years. The reason for the 1-year statement is usually due to the storage risk (moisture absorption and acid value increase) after unsealing. For our unopened products, we specify a 24 month shelf life (calculated from the production date) and recommend retesting in the 12th and 18th months.
A: Yes. Our 3-hexanone is a fully synthetic product. No animal derived ingredients (BSE/TSE free) or phthalate plasticizers are involved in the production process. This is particularly important for customers of pharmaceutical intermediates and food contact materials. We can provide a full set of compliance statement documents with the order.
A: This is extremely rare because the melting point of 3-hexanone is very low. If flocs appear, it is usually not the crystallization of the product itself, but the ice crystals precipitated by trace water at very low temperature, or the coating on the inner wall of the old barrel falls off. If it is ice crystal, it will disappear after heating to room temperature and stirring. If it is a solid impurity, please keep the site immediately and contact us. This also re-emphasizes the importance of using new unlined steel drums.
A: Depending on the application. The boiling point of cyclohexanone (155 °C) is significantly higher than that of 3-hexanone (123 °C). If you need faster drying speed, 3-hexanone is a good substitute; However, if you rely on the high boiling point of cyclohexanone to level, you may need to adjust the proportion of other high boiling solvents in the formula to replace it directly.
A: We implement a strict “special tank” or “compatibility cleaning” strategy. If the tank is leased, we require the cleaning station to provide a wall wash test report to ensure that the previous cargo in the tank are not highly toxic substances or strong oxidants.
A: Our synthetic process does not use benzene, toluene or xylene as raw materials or solvents. Therefore, the product is essentially “benzene free”. This is very helpful to comply with California Proposal 65 and some regulations on children’s toy coatings.
A: The acidity of the standard is controlled below 0.02%. For extremely sensitive customers, we can add a layer of activated alumina or alkaline resin adsorption column before filling to further reduce the acidity to <0.005%. This is a customized service, which requires advance scheduling.
A: This is in accordance with the IMDG Code. 3-hexanone has no independent UN number and must be classified under UN 1224. The bill of lading (B/L) must display the Proper Shipping Name (PSN), that is, “ketones, liquid, n.o.s.”. Usually, we will add “(contains: 3-hexanone)” in the description for identification.
A: In most countries (including China, USA, and EU), 3-hexanone is currently not included in the control list of precursor chemicals. This is different from its isomers (like 2-hexanone), which makes its international trade and procurement process relatively simple. However, the customer still needs to verify the latest local regulations.
A: We welcome long-term partners to conduct quality system audits. We have passed ISO 9001:2015, ISO 14001 and ISO 45001 certification. For remote audit, we can provide desensitized versions of batch production records, equipment calibration certificates and raw material traceability files.
Our Laboratory
Our Factory
Professional service
References & Data Sources
-
1. Product Identification & Isomer Toxicity
3-Hexanone Compound Summary (CID 11509). PubChem, National Library of Medicine (NIH). [Link]
Toxicological Profile for 2-Hexanone (Neurotoxicity Comparison). Agency for Toxic Substances and Disease Registry (ATSDR). [PDF] -
2. Physicochemical & Thermodynamic Properties
3-Hexanone Thermochemical Data & IR Spectrum. NIST Chemistry WebBook, SRD 69. [Link]
CAMEO Chemicals Database (Search: Ethyl Propyl Ketone). NOAA Office of Response and Restoration. [Search] -
3. Flavouring Specifications (JECFA)
Evaluations of the Joint FAO/WHO Expert Committee on Food Additives (JECFA No. 281). World Health Organization (WHO) / FAO. [Link] -
4. Global Transport & Regulations (IMDG/IATA)
UN Model Regulations (Dangerous Goods List, UN 1224). UNECE Sustainable Transport Division. [Source] -
5. REACH Registration & GHS Labeling
Substance Information: Hexan-3-one (EC 209-645-4). European Chemicals Agency (ECHA). [Link] -
6. PPE Selection & Occupational Safety
NIOSH Pocket Guide to Chemical Hazards (Ketones & Gloves). Centers for Disease Control and Prevention (CDC). [Link]